Add logging; don't relay signal from stub after seeing EOF.

edit/history.go

@@ -20,6 +20,7 @@ func (ed *Editor) appendHistory(line string) {
 			// TODO(xiaq): Report possible error
 			ed.store.AddCmd(line)
 			ed.store.Waits.Done()
+			Logger.Println("added cmd to store:", line)
 		}()
 	}
 }

eval/builtin_func.go

@@ -385,6 +385,7 @@ func cdInner(dir string, ec *EvalCtx) {
 				// XXX Error ignored.
 				store.AddDir(pwd)
 				store.Waits.Done()
+				Logger.Println("added dir to store:", pwd)
 			}()
 		}
 	}

stub/badsignal.go

@@ -5,7 +5,7 @@ type BadSignal struct {
 }
 
 func (bs BadSignal) String() string {
-	return "bad signal:" + bs.Error.Error()
+	return "bad signal: " + bs.Error.Error()
 }
 
 func (BadSignal) Signal() {}

stub/stub.go

@@ -122,6 +122,9 @@ func relaySignals(reader io.Reader, sigch chan<- os.Signal) {
 		_, err := fmt.Fscanf(reader, "%d", &signum)
 		if err != nil {
 			sigch <- BadSignal{err}
+			if err == io.EOF {
+				break
+			}
 		} else {
 			sigch <- syscall.Signal(signum)
 		}